1. Field of the Invention
This invention relates to an end face polishing method for polishing a free end portion of an optical fiber to the shape of a wedge by an end face polishing machine.
2. Description of the Related Art
The connecting of a pair of optical fibers together in an abutted state has heretofore been done by a machine equipped with a semiconductor laser provided on the side of a free end of one optical fiber and adapted to emit the light received from the optical fiber, and a pair of optical systems adapted to turn the light from the semiconductor laser into a collimated beam and focus the beam on the other optical fiber.
In such a machine, it is necessary that the semiconductor laser and optical systems be arranged with a high accuracy with respect to the two optical fibers. When the positional accuracy of these parts arranged is low, an input loss becomes large.
Under the circumstances, a method of polishing a free end portion of one optical fiber to the shape of a wedge without providing a semiconductor laser at the free end of this optical fiber, and emitting from the polished end face the light identical with that from the semiconductor has been proposed.
When this optical fiber the free end portion of which is formed to the shape of a wedge is used, it is not necessary to carry out a position setting operation for disposing the semiconductor laser, so that a polishing machine assembling steps can be simplified.
It is necessary in such an optical fiber to set the eccentricity of a core thereof not higher than 1.0 xcexcm. To meet the requirement, the free end portion of the optical fiber is polished to a certain extent by an optical fiber polishing machine, and the resultant optical fiber is then removed from the polishing machine to ascertain the polishing accuracy. Therefore, when the optical fiber polishing operation is restarted after setting the optical fiber on the polishing machine again, it is difficult to carry out an optical fiber-positioning operation, and the polishing accuracy is deteriorated due to a scatter of the position in which the optical fiber is set.
The repeated removing of the optical fiber from the polishing machine causes scratches on and the breakage of the optical fiber to occur, and the yield of polished products to decrease.
The present invention has been made in view of these circumstances, and provides an end face polishing method capable of improving the optical fiber polishing accuracy, reducing the optical fiber polishing time and simplifying the optical fiber polishing work.
The invention also provides an end face polishing machine equipped with a polishing board supported on a machine body and an optical fiber retaining jig, and being adapted to polish a free end portion of the optical fiber retained by the jig into the shape of a wedge by a polishing member fixed to the polishing board, the polishing machine including an inspection unit adapted to take a picture image of a free end portion of the optical fiber retained by the jig and ascertain the position of a core on an end face of the optical fiber.
The invention further provides an end face polishing method using a polishing board supported on an end face polishing machine body and an optical fiber retaining jig, and adapted to polish a free end portion of the optical fiber retained by the jig into the shape of a wedge with a polishing member fixed to the polishing board, the method being carried out by taking a picture image of the free end portion of the optical fiber by an inspection unit while light is being passed through the optical fiber, without removing the jig-fixed optical fiber from the jig, and regulating a polishing quantity of the optical fiber while ascertaining the position of a core on the end face of the optical fiber.